With the development of computer technologies and network popularization, remote desktop technologies have found increasingly wide application in current enterprise office environments. In the remote desktop technologies, specifically, content displayed on a computer screen is transferred through a network to another remote display in the network for displaying. For example, a Microsoft Windows system provides a remote login program, mstsc.exe, which is a common remote desktop program.
With the rapid development of cloud computing technologies and the popularization of the application of the cloud computing technologies, the cloud computing technologies bring new development opportunities for application of a remote desktop. People increasingly apply remote desktop technologies to virtual machines in a cloud computing system; in this way, people can separately apply, to local clients, applications on virtual machines by means of the remote desktop technologies, thereby implementing full application of the cloud computing system.
For network application, in the remote desktop technologies, an end where a user is located is marked as a client, and an end (which may be, but is not limited to a virtual machine) where each application program is practically located is a server configured to provide a service for the user. Each client applies an application on each server by applying a virtual remote desktop technology as conveniently as a user applies a program on a local client so that user experience is significantly improved.
With the development of the remote desktop technologies and the increase of multimedia application demands of people, the remote desktop technologies are not only limited to remote screen displaying, and further include remote sound transfer and the like.
In a practical application in a network, server and network bandwidth resources are limited. If the CPU usage of a server is excessively high, the server easily becomes busy, in which case the server responds to an application of each client at an excessively low speed, or even the server may crash because of excessive applications, affecting use experience of a user. In addition, if the server sends an excessively large amount of network data to each client, network congestion also occurs easily. Data processing of multimedia information (for example, conventional multimedia data and flash multimedia data) and multimedia network transmission occupy major resources (central processing unit (CPU) and network resources).
A multimedia redirection technology is a network application technology mainly for solving technical problems such as a CPU overload of a server and an excessive amount of network data. In the redirection technology, a client mainly sends a data stream of an original undecoded media file (whose data packet is much less than that of decoded data) to a client by using a virtual remote desktop technology, and decoding (or data processing of stream media before playing) and playing are performed at the client rather than at a server end, thereby significantly reducing CPU usage of a server and occupation of network bandwidth.
Flash is a specific type of multimedia data, flash redirection thereof is specifically that: when a browser at a server end plays flash content, a server captures the flash content, sends a data stream corresponding to the captured flash content to a client, and redirects the data stream to the client so that rendering of the flash content is performed in a window of the client instead of at the server end, thereby reducing CPU usage of the server end and occupation of network bandwidth.
By using flash redirection as an example, in a processing manner of flash redirection in the prior art, after a user logs in to a server by means of a network by using a remote desktop technology, opens a browser on the server, and opens a web page having flash multimedia content, the server triggers a flash redirection process according to the opening of the browser. Flash redirection processing is implemented so that the user implements flash playing on a client.
In a research process of the present invention, the prior art at least has the following defects.
By using flash redirection as an example, in an existing flash redirection technology, when a client logs in to a virtual desktop again to use a virtual-desktop service after a last disconnection, if a multimedia instance that is not shut down exists before the last disconnection, non-flash content such as a blank or a black screen is presented in a window of the client, causing loss of flash content, resulting in great inconvenience to application performed by a user, and affecting practical application performed by the user.